#include  <cstdio>
#include  <algorithm>
#include  <iostream>
using namespace std;

int main(int argc, char *argv[])
{
	int m,n,a[900],total,counter = 0;
	while( scanf("%d%d",&m,&n) && m != 0 )
	{
		for( int i = 0 ; i < m*n ; ++i )
			scanf("%d",&a[i]);
		scanf("%d",&total);
		sort(a,a+m*n);
		int sum = 0,v = 0;
		double meter = a[0];

		int i;
		for( i = 0 ; i < m*n-1 ;  )
		{
			if(total == 0)
				break;
			int k = 1;
			int j = i + 1;
			while(a[j] == a[i])
			{
				k++;
				j++;
			}
			sum += k;
			if( v + 100*sum*(a[i+k] - a[i]) <= total)
			{
				v += 100*sum*(a[i+k] - a[i]);
				meter = a[i+k];
				i += k;
				if(v == total)
					break;
			}
			else
			{
				meter += (total - v) / (sum*100.0);
				break;
			}
		}
		if(i == m*n-1)
		{
			sum++;
			meter += (total - v)/(sum*100.0);
		}
		if(total == 0)
			meter = 0;
		printf("Region %d\nWater level is %.2lf meters.\n%.2lf percent of the region is under water.\n\n",
				++counter,meter,100.0*sum/(m*n));
	}
}
